Psychophysical studies of auditory and tactile processing of acoustic patterns in speech and music and of visual patterns (lipreading) in speech. Evaluation with hearing-impaired persons of new hearing-aid designs and non-auditory sensory aids. Electrophysiological studies of cochlear-microphonic and auditory-nerve potentials in animals, and brain-stem evoked potentials in humans. Acoustical analysis of the source characteristics of voice, and normal and impaired articulation of speech. Evaluation of language development in young children. Anatomical, physiological and behavioral investigation of hearing loss following noise exposure.